Apparatus for testing materials



Feb. 24, 1925. 1,527,409

* G. A. HAssEL V AFPARATUS FOR www; MATERIALS Fileamay 28, 1920 Patented Feb. 24, 1925.

ienne PNTENT cenet.

susfrav A. nassen, or MCKELEsrbRr, PENNSYLVANIA.

`Ariznmvrus Foie TESTING MATERIALS.

Appiiea-mn aree May ze, 1920; serial No; 384,793.

We all' wiz-017e t may concern."

Be it kno-wn that I, Gnsrn'v A. Hass-nn, a citizen oft the United States, residing at McKeesport, in the county of Allegheny and State et Pennsylvania, have invented cerrtain newand usetnl improvements in Arp'- tensile strength, a test specimen has been prepared by either tlireading its ends er providing it with enlarged ends,` and then placing the test specimen in a testing machine i-n which the ends of the specimen are rigidly' gripped by grip er clamping devices.

This method? of rigidly gripping the ends oft the test specimen daring the test is o-bfjectionable and, further-5V the time and lab'cr expended rn preparing the test prece has been considerable. n

A stil-li further cbjectibnable teatureencountered under the present metl'rcdi of and apparatus employed for testing is due to the construction of the gripping er test piece clamping members and the cooperating testing machine parts; that is to say, on account of the construction, considerable time and labor is required in placing the specimen in position -for the test and removing it from the machine.

My invention is designed to overcome the objectionable features above referred to, and among the objects of the present invention are7 to provide a method of testing the strength of a member or article without rigidly or tightly gripping or clamping the member being tested; to provide simple and efiicient means for maintaining the test specimen in the desired position in the testing machine, said means constructed and adapted 'for readily placing the specimen in position and removing it from the machine; and to provide a new and improved construction and combination ci parts herein after described and claimed.

In the accompanying drawings which illustrate apparatus embodying my invention,

Fig. luis a side elevational view of a portionof a testing machine showing my im vention applied thereto5 F ig. 2, an enlarged detail sectional view particularly showing the test specimen holding or clamping means;

F 31, horizontal sectional view, the section being taken on line IIL-lll ot Fig; 2; y

Fig. t, aview similar to Fig, the section being taken on line IV-IV or" `Fig. 2; and

Fig; 5, an interior lace view of one membe-r of" a pair odi tests-pecimen holding or clamping means.

Referring teV the drawings, Q-Q designate upriglrtsfor standards oi? a portion of a testingmachiine-, 3 a vertically movable crosshead7 and' 4c a fixed cress-hea`d cit said machine. As the testing machine per se forms no part of my invention, I deem it unine'cessaily' to fully describe and illustrate the same.` y l As shown, the respective cross-heads are provided with wedge shaped openings 5 and 63 andi' represents a laterally extending opening formed in each cross-head and com-y nnmicating'with the Wedge shaped openings- '8 designates the test specimen and, as illustrated Vas preferred, the test specimenor piece is `formed at each et its ends with ahead to, beveledv sholnlders or faces Zr, and an annular collar 0. It will be understood that the operation of shaping the ends of the test specimen, as shown, is much more simple and of less cost than is the case where the ends of the test piece are threaded.

The clamping or test specimen retaining means are designed to be entered in the respective openings 5 and 6 of the crossheads and are of substantially the same construction, thereby making them interchangeable. Each clamp structure includes two similar wedge shaped members 9 9, each having a central longitudinally extending semi-circular bore l0, an opening 1l extending trem a side inwardly and communicating with the bore, and pockets 12 into which are placed the ends of coiled springs l".

At one end of the bore is a beveled wall 11i, the latter forming, when the clamps are assembled, a seat for the beveled shoulder or face of the test specimen-` The beveled wall 14 of each part merges into a semi-cin cular wall 15 adapted to encircle the annu* lar collar c ot the test piece.

For the purpose of moving the clamp d structures vertically relatively to the clamp receiving openings 5 -and 6, I provide each structure with an operating lever 16, the latter being pivotally mounted on a pin 17 supported on standards 18 extending upwardly from a plate 19 secured to the upper end oit each clamp section by bolts 20. 21. designates ay support carried on the upper ixed cross-head to Which the lever 16 is ulcrumed, and 22 represents an adjustable Weight mounted on the lever.

The test specimen may be readily placed within the clamp structures by spreading the members slightly and passing the specimen through the opening 7 of' each crosshead and the openings 11 of the clamps. It Will be understood that the two-part clamp will be automatically separated sufficiently to receive the specimen, by the action of the springs 13, when the clamps are moved outwardly a slight distance in the respective openings 5 and 6.

In Fig. 2, the upper clamp structure is shown closed and loosely clamping or retaining the test specimen, While the lower clamp is shown separated, orin the position to receive or permit the removal of the specimen,

Then the parts are in position to subject the specimen to a test, it Will be noted that it is not rigidly clamped or gripped, although securely maintained in the desired operative position, with the beveled faces of the specimen in contact with the beveled Walls of the clamps, thereby loosely clamping the specimen or the ends thereof, and it will be seen that the specimen is held against movement only in the direction of the testing strain, While it is free to move angularly in other directions, so that it can adjust itself to proper positon if the opposed clamps of the testing device should be slightly out of alinement.

lVhat I claim is:

1. The combination with a testing machine, clamping means thereon adapted to hold specimens that have been provided with heads thereon, said clamping means comprising cooperating jaws for egaging one end of the specimen having an opening therein of greater diameter than the stem of the specimen to be tested and having a recess therein to receive the head of a specimen, the arrangement being such that there may be relative angular movement between the aws and the specimen when under tension.

The combination with a testing machine having a iXed and a movable cross head each provided with a clamp receiving opening and a side opening communicating With the first mentioned opening, a two-part clampy structure located in each of the crosshead openings, each clamp structure having a central bore and a side opening communicating with the bore and registering With the side opening of the cross-head.

3. A test specimen clamping device including a two-part structure having a central bore, springs interposed between the parts and exerting pressure to separate the parts, and a side opening communicating with the central bore,

In testimony whereof I affix my signature in presence of two Witnesses.

GUSTAV A. HASSEL lVitnesses J. M. GnoGI-IEGAN, Lors VINEMAN. 

